The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some of such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.
Wireless communication systems are constantly under development. Developing systems provide a cost-effective support of high data rates and efficient resource utilization. One communication system under development is the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) later also known as LTE-Advanced (LTE-A). The LTE is designed to support various services, such as high-speed data, multimedia unicast and multimedia broadcast services.
One aspect under development is the concept of small cells. It has been proposed that under a macro cell serving a large area there would be a small cell layer or a number of smaller cells with local area coverage. The small cells could reduce power consumption of the base stations and user equipment (UE), and they could be used to offload traffic from the macro cell layer to a small cell layer, and also potentially enable some new service types in the future.
It has been proposed that UE could have a dual-connectivity for the macro cell layer and for the small cell layer. The dual-connectivity may mean a logical relationship of the UE to the two different cell layers. The UE may have physical links established for the macro cell and small cell layers simultaneously, or the UE may switch the physical resources in time, or the UE may run its logical macro connection via the small cell. Collaborative transmissions on a small cell layer are not excluded.